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I/O Response Time in Tag Data Links Section 10-3
Note (1) When one of the listed CPU Bus Units is mounted in a CS-series Long-
distance Rack, the I/O refreshing time is extended by the distance to the
Rack in which the Unit is mounted, regardless of the model of the CPU
Unit. The following graph shows the coefficients (2 and 3) required to cal-
culate this effect.
(2) The additional time for CJ2H CPU Units with unit version 1.1 or later will
be as follows if high-speed interrupts are enabled.
0.1 ms + Number of words transferred
× 0.87 µs
10-3-4 Tag Data Link I/O Response Time Calculation Example
When using the tag data link functions of the EtherNet/IP Unit or CJ2H built-in
port, there is a time lag between the point when the data link area’s data
changes due to an input at a node and the point when the change is output at
another node’s data link area. This time lag is called the tag data link
I/O response time.
This example shows how to calculate the minimum and maximum I/O
response times in the following configuration for connection 1 opened
between node 1 and node 2.
CPU Unit Effect of EtherNet/IP Unit or
CJ2H built-in port only
Total effect when tag data links are being used
CJ2H CPU Rack: 0.1 ms
Expansion Rack: 0.13 ms
CPU Rack: Value from left column + 0.1 ms + No. of words trans-
ferred × 0.33 µs (See note 2.)
Expansion Rack: Value from left column + 0.1 ms + No. of words
transferred × 0.45 µs
CJ2M CPU Rack: 0.14 ms
Expansion Rack: 0.16 ms
CPU Rack: Value from left column + 0.02 ms + No. of words trans-
ferred × 0.78 µs
Expansion Rack: Value from left column + 0.02 ms + No. of words
transferred × 0.92 µs
CJ1 0.25 ms 0.25 ms + 1.5 ms + (Number of words × 1 µs)
CJ1M 0.17 ms 0.17 ms + 0.1 ms + (Number of words × 0.7 µs)
CJ1-H 0.1 ms 0.1 ms + 0.1 ms + (Number of words × 0.7 µs)
CS1 0.2 ms 0.2 ms + 1.5 ms + (Number of words × 1 µs)
CS1-H 0.1 ms 0.1 ms + 0.1 ms + (Number of words × 0.7 µs)
Long-distance
Rack
0.2 ms × Coefficient 2 (0.2 ms × Coefficient 2) + 1.5 ms + (Number of words × 1 µs ×
Coefficient 3)
Coefficient
Distance to Long-distance Rack (m)
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